Automatic popcorn popping method

ABSTRACT

Method and apparatus for automatically popping corn in heated seasoning oil. A rotary valve disk in a closed pot is operated to correlate the phases of corn and salt input into the pot, cooking, steam discharge, and discharge of popped corn and unpopped kernels by means of an air current. A deflector plate directs the air into a path for optimum corn evacuation through a downwardly facing outlet. The air current sweeps the corn and kernels through the outlet and along a curved path whereby the corn and kernels are separated from the air current. Thereafter the air current is recirculated into the pot. &#34;Old maids&#34; in the discharge of popped corn from the pot are trapped and separated therefrom for removal through a chute in one form, or through a screen in the bottom of the display case in another form.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of application Ser. No. 283,932 filedAug. 25, 1972 now U.S. Pat. No. 3,812,774 which in turn is a division ofSer. No. 875,759 filed Nov. 12, 1969 now U.S. Pat. No. 3,697,289.

BACKGROUND AND OBJECTS OF THE INVENTION

This invention relates to automatic popcorn popping machines.

Automatic popcorn popping machines have been provided for use intheatres, clubs, amusement parks, and other establishments to supply thepublic's demand for popcorn. These machines, however, have manydisadvantages and limitations. A majority of the conventional poppersmust employ hot air popping rather than the more desirable oil popping.Operation of the prior art popping machines is not entirely automatic inthat many of the steps must be performed manually, requiring thepresence of an operator. Thus, certain of the machines require manualcontrol of filling the popper with corn, seasoning oil and salt. Inthese machines the pot must be opened for each pop, and this introducesthe possibility of contaminants entering the pot and mixing with thepopped corn, as well as the possibility of injury to the operator.Popping machines of the open-pot type also quickly lead to fouling andunsightliness of the display case after only a few pops resulting fromcondensed steam and waste oil.

Previous popping machines have not been entirely successful in providinga salable product having the desirable qualities of uniform flavor,tenderness and appearance. These have varied depending upon factors suchas operator judgment or machine limitations in measuring the amount ofraw products in the supply hoppers, time length for each cycle, thetemperature in the pot during a pop, control of steam and waste oileffluent from the popper, and separation of "old maids" from the poppedcorn. In these poppers the operation has not been failsafe such that thecycle is interrupted should any of the supplies be insufficient for apopping cycle. Also, if the operation stops during any cycle, there isno assurance the machine will continue with the correct cycle sequenceupon restart. Previously, salt injection into the popper has been aproblem, and conventional machines have not successfully metered theprecise amount of salt into the popper for uniform results.

Conventional popping machines also do not lend themselves to a continuedseries of popping cycles untended by an operator, and they have noprovision for selectively controlling the rate of popping and the totalnumber of pops in a completely automatic process.

Another object is to provide a fully automatic machine for popping cornin heated seasoning oil.

Another object is to provide a popcorn popping machine having a closedpot throughout a series of popping cycles eliminating the possibility ofcontamination of a pop, injury to the operator, and effluent dischargeinto the display case.

Another object is a popping machine providing air evacuation of thepopped corn product from the popper into the display case.

Another object is a popping machine providing air evacuation of thepopped corn with a trap for removing "old maids" from the product anddirecting them into a chute for subsequent removal.

These and other objects and advantages of the invention will becomeapparent to those skilled in the art when the following specification isread in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION

The invention provides a popping method of operation with fullyautomatic functions controlled in accordance with a predeterminedprogram providing an optimum popcorn product of uniform flavor,tenderness, and appearance. The corn is popped in hot oil enabling theuse of a lower popping temperature. A closed popping pot reduces thepossibility of contaminants mixing with the product and affords removalof objectionable steam and waste oil effluent. The material suppliescorn and salt are precisely metered in a predetermined quantity for eachpopping cycle, and are conveyed into the pot by an air current removingobjectionable moisture therefrom and providing a positive hopper airpressure at all times. The raw corn is fed from a large bin at the baseof the machine upwardly to a supply hopper above the pot by an airconveyor. Seasoning oil contained in a supply at the base of the machineis delivered upwardly to a metering reservoir above the pot by a pump inthe oil supply through a telescoping supply tube and support. Heatingmeans are provided to melt that portion of the solidified oil adjacentthe pump inlet and telescoping tube for rapid start-up. As the oil isconsumed, the pump melts additional oil and moves downwardly with thelevel of the solidified oil. An oil metering device is providedmeasuring the precise quantity of oil required for each pop by fillingup above a predetermined level in the reservoir, drawing down the oil toa level which is vertically adjustable, and then injecting the charge ofremaining oil into the pot. The oil level in the reservoir iselectronically sensed to signal the control circuit for continuedcycling, or oil re-supply, as required. A rotary valve disc is indexedin accordance with a predetermined program and exposes a series ofinlets and outlets including the inlets for air, corn and salt supplies,outlet to the condenser, and product outlet for communication betweenthe pot interior and display case. A deflector plate is disposed belowthe air inlet for directing the air current into a path around the innerperiphery of the pot for carrying the popped corn upwardly to adischarge tube for delivery to the display case. In a modified form theunpopped corn or "old maids" are removed from the popped corn by a trapand delivered through a discharge chute for subsequent removal. During apopping cycle the steam and vaporized oil are removed from the pot by avacuum created by a venturi in a self-cleaning condenser. In anothermodified form a major portion of the steam is condensed within an exitconduit having a dome disposed above a gutter receiving the condensedwater and preventing the same from draining back into the pot. Anagitator blade in the pot has a configuration with its leading edgedefining a forward rake to sweep the popped corn radially inward forevacuation into the discharge opening. The drive for the agitatorincludes a spring-biased driving shaft mounted from above andinterfitting with a socket in the agitator base permitting easy openingand closing of the agitator and hotplate for cleaning purposes. Anelectronic control circuit is provided to correlate the various machineprocesses, provide automatic warning of insufficient material supplies,provide a visual indication of machine cycling, provide selectivevariation of material supplies and popping times for maximum popcornvolume, tenderness, flavor and appearance, provide either continualpopping or a selected number of pops at any desired rate, andautomatically count the number of pops for supply and usage control.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of an automatic popcorn popping machineembodying features of the invention.

FIG. 2 is a side elevation view of the machine of FIG. 1.

FIG. 3 is a sectional plan view taken along the line 3--3 of FIG. 1.

FIG. 4 is a front elevation view taken along the line 4--4 of FIG. 2.

FIG. 5 is an elevation cross-sectional schematic view of a componentcondenser element in the invention.

FIG. 6 is a top plan sectional view taken along the line 6--6 of FIG. 4.

FIG. 7 is a fragmentary section view of the corn-salt hopper taken alongthe line 7--7 of FIG. 6.

FIG. 8 is a sectional view of the hopper taken along the line 8--8 ofFIG. 7.

FIG. 9 is a fragmentary elevation view, partially in cross section,taken along the line 9--9 of FIG. 6.

FIG. 10 is a cross-sectional elevation view of the popping pot andassociated elements of the invention.

FIG. 11 is a fragmentary top plan view of the agitator and hot plateassemblies.

FIG. 12 is a side elevation view, with portions removed for clarity, ofthe popping machine showing features of the corn supply and airconveyor.

FIG. 13 is a partial front elevation view, with portions removed forclarity, illustrating the seasoning oil supply and pump with telescopingsupport and feed tube and heater elements.

FIG. 14 is an elevation view to an enlarged scale of the oil pump andheater elements of FIG. 13.

FIG. 15 is a bottom view of the oil pump of FIG. 14.

FIG. 16 is an elevation sectional view of the oil metering assemblytaken along the line 16--16 of FIG. 6.

FIG. 17 is an elevation sectional view of the oil metering assemblytaken along the line 17--17 of FIG. 6.

FIG. 18 is a fragmentary top plan view illustrating an operatingposition of the rotary valve disc with respect to its associated portscontrolling the processes for the pot, and including the control switchpositioning.

FIGS. 19 A and B comprise a schematic diagram of the control circuit forthe invention.

FIG. 20 is a vertical section view of a modified form illustrating asteam condenser connected between the pot outlet and main condenser.

FIG. 21 is a fragmentary sectional view of a modified form illustratinga trap for removing "old maids" from the air current evacuating popcornfrom the pot.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, and particularly to FIGS. 1--3, a preferredform of the automatic popcorn machine is illustrated generally at 10.

Popcorn machine 10 comprises a main frame or supporting structure 12including a lower supplies section 14, a central display case 16, apopping pot assembly 18 depending into the case, and an upper section 20containing the systems control circuits, operating mechanisms, andmetering devices with associated control knobs and indicator lights.

Lower supplies section 14 is provided at its front with various accessdoors for resupplying the corn and oil supplies and removal of wasteproducts. Access door 22 opens outward from the frame for access to aseasoning oil container insertable into the bottom of frame 12. Accessdoor 24 opens forwardly for convenience in filling a raw popcorn binwithin the frame. Lockable door or drawer 26 may be provided forsafeguarding cash. An electrical outlet 28 may be provided for poweringaccessory equipment. An access door 30 is provided and hinges foroutward swinging movement to provide access to the mechanical equipmentlocated in the bottom of the frame and for removal of the "old maids"bin and condensate pan.

Display case 16 includes a front wall defined by a pair of outwardlypivoting transparent doors 32, 34, providing access to the interior ofthe case for bagging popcorn and cleaning purposes. A forward pivotingdoor 36 is also provided below the transparent doors for removingpopcorn. The display case sides 38, 40 and back 42 are preferablytransparent for customer attention and product appeal. Referring to FIG.3, a suitable screen 44 is provided in the bottom of the display case topass the fines and "old maids" downwardly into a chute leading into abin for subsequent removal. Popping pot 18, described in greater detailhereinafter, delivers the popped corn into the display case through cone46 in an attention getting shower onto the bottom of the case.

Upper portion 20 includes on its front face a control panel 48 includingthe selector knobs and indicator lights to be presently described. Alockable control cover panel 50 is slideable along the front face ofpanel 48 and, when locked in position, prevents unauthorized usage ofthe machine.

Raw Corn Storage and Conveyor

Referring to the cross-sectional elevation view of FIG. 4, elements ofthe raw corn storage and conveyor system are illustrated in greaterdetail. A large corn supply bin 52, capable of storing up to 100 lbs. ofcorn, is mounted in a lower portion of frame 12. The bin is providedwith a trough-shaped bottom 54 directing the raw corn downwardly intoair-conveyor device 56 which automatically delivers a supply of corn, asrequired, upwardly into corn hopper 58 disposed in upper section 20above pot 18. Air conveyor 56 includes a suitable blower 60 driven by apreferred electric motor 62. The blower draws inlet air through opening64 and directs it through transverse conduit 66 upwardly throughvertical conduit 68 passing along the rear wall of the display case, asbest illustrated in FIG. 12. Corn from bin 54 is deliveredintermittently through the air stream from the blower by metering device72 operated by a signal from the control circuit indicating that aresupply of hopper 58 is required. Metering device 72 may be anysuitable valving arrangement, and preferably comprises a conventionalscroll or auger conveyor horizontally axised with an inlet opening at 74communicating with bin 54 and with an outlet at 76 communicating withthroat section 78 comprising a section of the air stream conduit.Metering motor 80 driving the auger is actuated responsive to a cornresupply signal until terminated responsive to corn level sensors inhopper 58 indicating that a sufficient quantity of corn has beensupplied for an additional charge of corn into the pot.

The upper section of vertical conduit 68 passing through display case 16is preferably formed of a transparent material such as plastic affordingan attractive display of corn delivery for public viewing.

With the corn supply in bin 52 at the lowermost portion of the machine,reloading through access door 24 is more easily and convenientlyaccomplished as opposed to a corn supply location above the popper. Atthe same time, the lower corn storage location is cooler and thus doesnot dry the corn as fast, as opposed to a location closer to the warmerportion of the machine near the popper. The air feed is a simple andinexpensive method of deliverying a relatively small amount of cornintermittently on a demand basis. Neither the auger metering device northe air conveyor itself are injurious or damaging to the corn kernels.

Corn and Salt Hopper 58

Referring to FIGS. 7 and 8 hopper 58 is shown in greater detail. In thepreferred form, the hopper is divided into a corn reservoir 82 and saltchamber 84 by means of center partition 86, although the two supplyreservoirs could be separated into individual chambers. The corn andsalt supplies are in juxtaposition to simplify and inprove injection ofthe charges into the popper, as described hereafter.

Corn reservoir 82 is closed at the top by upper wall 90, at the sides bypartition 86 and side wall 92, and at the ends by end walls 94, 96converging together below to define a narrowed throat section 98. Thehopper is mounted by means of base 100 on top of a support plate 102separating display case 16 from upper section 20. Throat section 98 ofthe hopper is in vertical registry with an opening 104 provided in plate102, and this opening in turn communicates with popping pot 18 upon afill cycle of the rotary valve apparatus 106 of FIG. 18.

An inlet opening 108 is provided in end wall 94 of the corn reservoircommunicating with conduit 70 of air conveyor 56. An outlet 110 isprovided in the other end wall 96 and communicates with an air outletconduit 112. A screen 114 is provided over opening 110 to retain thecorn within the reservoir. During operation of the air conveyor, cornentering the reservoir through opening 108 refills the reservoir whilethe conveying air exits through opening 110.

The level of corn in the reservoir is sensed by a pair of capacitorplates 116, 118 mounted at the desired level within the reservoir torespective side wall 92 and partition 86. As the corn fills within thereservoir and occupies the space between the capacitor plates, thecapacitance across the plates changes. This actuates the control circuitthrough leads 120, 122 for terminating operation of the corn metermotor, and energizes the corn indicator light for continuation of thecycling operation in a manner described hereinafter.

During injection of the corn charge into the pot, the valve hole oropening 396 of valving apparatus 106 moves into alignment with hopperthroat section 98. The corn is swept into the pot from the hopper byboth the action of gravity and a stream of air from air conveyor outlet70 moving down through throat section 98 into the pot and exitingthrough the lower opening 124 of cone 46, as best seen in FIG. 10. Thecontinued air pressure in the hopper from air conveyor 56 insures an airflow into the pot preventing any effluent from entering and fouling thehopper. This continued air flow, although principally effective duringfilling, provides insurance of a positive pressure in the hopper toprevent effluent leakage at all times.

After the corn has been injected, a change of salt is then introducedinto the pot from salt chamber 84. The salt chamber is closed at itssides by partition 86 and side wall 126, and at its ends by end walls 94and 96 coextensive with the corn reservoir. The top of chamber 84 isprovided with a fill hole 128, and the bottom is confined by housing 130provided with an opening 132 communicating with a charging valve 134. Asalt bin 136 is pivotally mounted at 138 within chamber 84. Bottom wall140 of the bin slopes downwardly from the pivot point to a relativelysmall spout or opening 142. The spout is adapted to move into opening132 and act as a funnel for filling the charging valve 134. Bin 136 isyieldably biased by suitable means such as spring 144 upwardly withinthe salt chamber, or clockwise as viewed in FIG. 8. A normally closedswitch 146 is mounted on chamber wall 126 and is adapted for contactwith salt bin 136 for opening when the bin is in its upper position, andfor closing when the bin pivots away.

Salt bin 136 preferably has a capacity on the order of 61/2 pounds,adequate for from 75 to 100 pops. With the bin filled with salt, it willpivot counter-clockwise by gravity against the force of spring 144 toclose switch 146, which in turn signals the control circuit to light thesalt indicator light and condition the circuit for continued cycling. Assalt si gradually used up so that an insufficient supply remains in thebin for continued popping, spring 144 will overcome the weight of thebin, pivot it clockwise, and thereby open switch 146 to signal thecontrol circuit to stop the fill cycle and turn off the salt lights sothat the salt supply must be replenished.

Charging valve 134 comprises a spool valve 148 axially slidable inhousing 130 underneath salt chamber opening 132 by the action ofsolenoid 150 operatively connected with valve stem 152. A return spring154 is provided at the opposite end of valve stem 152 for returningvalve 134 to the position illustrated for receiving a supply of saltfrom bin 136. In this position, salt drains from spout 142 throughopening chamber opening 132, and into cavity 156 formed between thelands of the spool valve. The volume of this cavity is selected toprovide sufficient salt for one pop. The salt draining through spout 142will automatically stop after the cavity is filled to a level just abovethe lower edge of the spout.

During a salt charging or filling operation after the charge of corn hasbeen injected into the pot, solenoid 150 is actuated by the controlcircuit to move spool valve 148 to the left so that the salt in cavity156 is swept into the pot by gravity and the air current previouslydescribed. A shield 158 comprises a section of a cylinder secured at oneside to partition 86, and is adapted to slideably receive spool valve148. The lower section of shield 158 is cut away at 160 to allow thesalt to drop through by gravity and be swept along by the air stream.This air injection of the salt into the pot serves to dry the salt andprevent fouling or sticking of the component elements, and at the sametime insures that all of the salt in each charge completely enters thepot for popping.

Seasoning Oil Pump System

The seasoning oil pump system includes a pump assembly 160 disposedwithin a seasoning oil bucket or vessel 162 positioned at the bottom offrame 12 for easy replacement, as illustrated in FIGS. 4 and 13. Thepump assembly is adapted to intermittently pump a supply of oil on ademand basis from bucket 162 upwardly through feed line 164 into oilreservoir 166 mounted above support plate 102 and positioned forinjecting an oil charge into pot 18, as explained hereinafter. Thepreferred seasoning oil would be coconut oil, although otherconventional popping oils may be used with the invention.

The seasoning oil useful with the invention solidifies at roomtemperature. The invention provides a means for melting a small quantityof the oil required for a number of initial popping cycles without thenecessity of melting the entire contents of the oil bucket. Thisprovides a more rapid start-up of the machine, as well as requiring lesspower.

Pump assembly 160 is adapted to move downwardly on the surface of thesolidified oil while guided by a telescoping feed line 168 andtelescoping support 170, as best seen in FIG. 14. A bracket 172 mountedon frame 12 supports the outer telescoping member 174 of feed line 168,and outer telescoping member 176 of support 170. Feed line 168 is arigid conduit secured at its lower end to pump unit 178, and slideablyreceived at its upper end within outer telescoping member 174. Similary,telescoping support 170 is mounted at its lower end to the pump unit andis slideably received at its upper end with telescoping member 176. AnO-ring seal 180 is mounted within the lower inner periphery of member174 to provide a fluid-tight seal with feed line 168. The telescopingfeed tube eliminates the requirement for flexible hosing which otherwisecould kink and interfere with pump operation.

Pump unit 178 comprises a fluid pump, such as a conventional gear-typepump, not shown, mounted within a housing 182 and with a pump inlet 184underneath the housing, as best seen in FIG. 15. The pump is driven by asuitable electric motor 186 mounted for movement with the pump housingon an upwardly extending bracket 188. The motor is mounted at asufficient elevation above the pump unit so that the motor is clear ofthe melted oil after the pump has dropped to its lowermost position. Thepump is driven from the motor by a suitable drive shaft, not shown,extending along bracket 188.

A lift knob or handle 190, Fig. 4 and 13, is secured to bracket 188 andis slideable in a vertical guideway 192 formed in a plate 194 secured toframe 12. When it is desired to remove or insert an oil bucket 162, lifthandle 190 is raised until the lower end of pump unit 178 clears thebucket. With the new bucket in place the pump is lowered until it restson the seasoning oil within the bucket.

The room temperature, solidified seasoning oil is melted for pumping byheating elements 196 and 198, which may be conventional electricalresistance-type heating elements in suitable tubing or the like andconnected in the control circuit. Lower heating element 196 is coiled ina serpentine path for melting oil at the base of the pump unit. Thepurpose is to both melt oil around pump inlet 184 for rapid start-up,and also to melt a path down through the seasoning oil as oil isconsumed and the pump gradually moves downwardly. Heating element 198extends vertically in a serpentine path or the like along telescopingfeed tube 168, and may be of the conventional electrical resistance-typeheater. The purpose of heater 198 is to both heat the oil within feedtube 168, which may have solidified after a length of time following aprevious pumping cycle, and also to melt a path through any solidifiedoil which may be above pump housing 182 during start-up so that pumpoperation can draw air down, thus preventing pump cavitation. Aftermachine operation progresses for a number of pops, the heaters willgradually melt the entire oil in the bucket so that the pump movesdownwardly through the oil to the bottom of the bucket.

A pair of normally closed limit switches 200, 202 are mounted on frame172 adjacent telescoping support 170. Switch 200 is connected to cut offthe circuit to pump motor 532, and switch 202 resets the operatingcycle, when the pump unit is raised to its uppermost position. Aswitch-operating cam 204 mounted at the lower end of bracket 188 is inregistry with and operates the switches 200, 202 in its raised position.This provides a safety feature so that the pump is automatically turnedoff when raised out of the bucket.

The oil is pumped under pressure upwardly through outer telescoping feedmember 174 into fitting 206 connected with the lower end of feed line164, as illustrated in FIG. 13. Feed line 164 guides the oil upwardlyalong the rear corner post of the display case and across to inlet 208of oil reservoir 166. The overflow from oil reservoir outlet 210 isdirected through overflow conduit 212 adjacent to the inlet conduit,down the corner post of the display case and directly over the oilbucket which it empties into through outlet 214 opening directly toatmosphere.

Oil Reservoir and Metering System

Referring to FIGS. 16 and 17, oil reservoir 166 includes a housing 216defining a cavity or sump 218 closed at its upper end by cover plate220. Reservoir inlet 208 is connected with oil feed line 164 by means offitting 222, and communicates with a transverse bore 224 formed in thehousing. Bore 224 in turn communicates with a hollow level-adjustingtube 226 slideably mounted in the housing in vertical bore 228.Adjusting tube 226 is closed at its upper end and retains a compressionspring 230 functioning to yieldably urge tube 226 upwardly. A draininghole or opening 232 formed in the side of tube 226 providescommunication between reservoir cavity 218, the interior of tube 226,and bore 224.

An adjusting mechanism 234 is provided to selectively adjust thevertical position of tube 226 and thereby adjust the level of drain 232.Adjusting mechanism 234 comprises an adjusting knob 236 adapted to turnshaft 238 threadably mounted in cover plate 220 directly above the endof tube 226. A pivoting shoe adjustable mounted on the end of shaft 238bears against the end of tube 226. A lock nut 242 is provided to lockthe shaft and level adjustment tube in the selected position. Theadjustabe drain level of the invention is more accurate in chargemeasurement than previous methods valve pumps, etc. where temperaturevariation or inaccurate pump shut off affects filling volume. Also,adjustable invention provides a degree of safety in automation whereinonly a measured amount of oil can be displaced into the pot on eachcycle without the possibility of overfilling or overpumping.

Reservoir outlet 210 is connected with overflow conduit 212 by means offitting 244 and communicates with the reservoir cavity through bore 246.

A spring-loaded ball check valve 248 is provided to prevent trappedseasoning oil from hardening in the reservoir during shut-down. Valve248 includes a ball 250 yieldably urged upwardly by means of spring 252within bore 224. A drain plug 258 is provided for retaining spring 252in position. Check valve 248 is normally held in open position duringshutdown by means of drain shaft 260 contacting ball 250 at its end andyieldably urging the same downwardly by means of spring 262 mountedbelow drain shaft housing 264. Drain shaft 260 includes an upwardlyextending portion 266 slideably mounted in housing 264 and connected atits upper end 268 with electrically operated solenoid 270. Throughoutthe operating cycles of the machine solenoid 270 is operated to drawdrain shaft 260 upwardly permitting drain valve 248 to close. Duringmachine shut-down, solenoid 270 is de-energized permitting the spring tourge drain shaft 260 downwardly and open valve 248. Any oil remaining inthe reservoir will drain through the valve and thus cannot solidify inthe reservoir. This prevents the reservoir and metering device frommalfunctioning and permits rapid start-ups without the requirement ofheating the entire metering assembly and solidified oil.

A dump valve assembly 272, FIG. 17, is provided to direct the meteredamount of oil into the popper at the cycle time as influenced by thecontrol circuit. The dump valve assembly includes a valve head 274carried on valve stem 276 and yieldably urged into sealing engagementwith valve seat 278 by spring means 280. The valve stem in turn isconnected at 282 with electrically operated solenoid 284. Whenenergized, solenoid 284 lifts valve head 274 from seat 278 to opencommunication between the reservoir cavity and bore 286 in registry withan oil inlet opening 288 formed in plate 102. The oil inlet is at aradial position clearing rotary valve apparatus 106 for directing oilinto pot 18 by gravital flow.

An oil level sensing device 290 is provided to sense oil level in thereservoir and signal the control circuit for cycle functions. In thepreferred form, the sensors comprise three horizontal, vertical spacedcapacitor plates 292, 294 and 206 positioned at predetermined levelswithin the reservoir. Electrical leads 300, 302 and 304 attached torespective condenser plates signal the control circuit as the oil levelrises above at least two of the plates.

Assuming that dump valve 272 is closed and check valve 248 is closed forcycling, the control circuit will signal pump 178 to pump oil throughinlet 208 and drainhole 232 to fill the reservoir. As the oil levelgradually rises to a level which covers both plates 292 and 294, thecapacitors signal the control circuit to start the popping cycle. Thepump continues to fill the reservoir until the level rises above plate296, and this signals the control circuit to terminate the pumpingoperation. Should the pump fail to stop for any reason the overflow willharmlessly return to the oil bucket through outlet 210 and conduit 212.Also, the control circuit is timed to shut off after 10 seconds ofoperation to prevent damage to the pump should the pump run dry. It hasbeen found that approximately 5 seconds is sufficient time for the pumpto fill reservoir 166.

After the control circuit has signaled the pump to stop, oil will startto drain backwards through the drain hole 232, bore 224, inlet 208, andfeed tube 164 to pump 178. Pump 178 is provided with a conventionalbypass opening, not shown, through which this oil will drain. The oilcontinues to drain until it reaches the lower portion of drain hole 232.The amount of oil in the reservoir is now at the pre-selected amountwhich has adjustably been set into the metering device throughadjustment of mechanism 234. Following this, the control circuit signalssolenoid 284 to operate for opening dump valve 272 and permit thisquantity of oil to drain into the pot. In the preferred embodiment, themaximum extent of downward travel of level adjustment tube 226 is suchthat drain hole 232 is positioned so that a minimum setting of 4 ouncesof oil will be injected. The upper extent of tube 226 travel provides amaximum of 10 ounces of oil.

Popping Pot and Discharge Apparatus

Popping pot 18 is positioned in the display case below support plate 102for receiving the corn, salt and oil charges, for discharging steam andwaste oil upwardly into condenser outlet 306 for delivery to condensingsystem 308, for receiving inlet air through evacuation inlet 310, andfor evacuating popcorn through outlet conduit 312 and downwardly intothe display case through tube 46, as best seen in FIG. 10. Pot 18comprises a bottom hot-plate and agitator assembly 314 pivotally mountedat 316 to a housing 318, shown as cylindrical, mounted below supportplate 102 by suitable means, such as bolts 320. The lower edge of thehousing is mounted in sealing engagement with a groove 322 provided inannular support rim 324. Evacuation conduit 312 extends through anopening 326 in housing 318 downwardly to an opening 328 radiallycentered in the pot and spaced above hot plate 314 at a heightsufficient to permit popped corn to be swept upwardly through theconduit by a stream of air. Conduit 312 extends outwardly from the potthrough an opening 330 provided in upper cylindrical portion 332 of cone46, where it angles to a downwardly facing discharge outlet 334. Cornexiting from the pot through conduit 312 cascades downwardly throughcone opening 124 into the display case.

Hot-plate and agitator assembly 314 includes a casting 336 of flat,circular configuration embedded with a suitable heating element 338,such as a conventional electric resistence element connected by suitableleads, not shown, with the control circuit. A lower cover plate 340 issecured beneath the hot plate as a precaution against injury to theoperator. Upper annular rim 342 of casting 336 is in sealing engagementwith housing rim 324 preventing escape of steam and waste oil from thepot. A locking mechanism 344 mounted on rim 342 at a diametral positionfrom pivot 316 secures hot-plate assembly 314 against housing rim 324throughout a series of popping cycles. The locking mechanism preventsunauthorized or accidental opening of the pot during popping, inasmuchas it is not necessary to open the pot for either charging or popcornremoval. For cleaning purposes, locking mechanism 344 is releasedpermitting hot-plate assembly 314 to pivot downwardly at 316.

An agitator assembly 346 is mounted above hot-plate casting 336 forstirring the corn kernels during popping and sweeping the popped corninwardly for evacuation. The agitator assembly includes a central hub348 rotatably mounted on an upwardly extending spindle 350 supported ina recessed portion 352 of casting 336. A plurality of outwardlyextending, generally flat blades 354, 356 are mounted for rotation withthe hub in a clockwise direction as viewed in FIG. 11. The sharpenedforward edge of each blade has a radially outward forward rake withrespect to the axis of rotation. This provides a radially inwardsweeping action to move the popcorn towards hub 348 for more efficientevacuation through conduit 312. The lower base portion of hub 348 isprovided with an outwardly flaring skirt 358 functioning to direct thestream of air upwardly into conduit opening 328 during corn evacuation.

Agitator assembly 346 is rotated by drive assembly 360 extendingdownwardly from above the pot. The drive assembly includes a shaft 362having a preferred hexagonal cross-sectional configuration and slideablylocking with a hexagonal female socket 364 provided at the upper end ofagitator hub 348. Shaft 362 is spring-loaded from above by suitablemeans such as compression spring 366 mounted within a sleeve 368. Sleeve368 in turn is secured to a broached hexagonal nut 370 keyed forrotation with drive shaft 372 extending downwardly through a quill shaft374 of drive assembly 376 provided for operating rotary valve apparatus106. Drive shaft 372 is driven from a preferred electric motor 378during the popping cycle by suitable means, such as a worm geararrangement, not shown. The lower end 382 of hexagonal shaft 362projects through an opening 384 of the evacuation conduit, and isaligned with agitator socket 364 for driving engagement when hot-plateassembly 314 is closed, as illustrated in FIG. 10. When the pot isopened for cleaning, downward pivotal movement of the hot-plate andagitator quickly uncouples drive assembly 360 at the socket connection.When the hot plate is returned and locked in place the shaft and socketwill lock in driving engagement where there is correspondence betweentheir angular positions. If shaft 362 does not engage in the socket, itis urged upwardly against the spring which forces them in lockingengagement upon start-up of agitator motor 378. As a result, any angularor vertical misalignment between the shaft and mating socket will notprevent engagement of the agitator drive, thus simplifying opening andclosing of the pot for cleaning.

Rotary Valve Apparatus

The rotary valve apparatus 106 provides an accurate valving of thevarious processes into and out of pot 18 in timed relationship with apredetermined program under influence of the control circuit. The valvearrangement of the invention provides a mechanical memory to assist theelectronic system to prevent loss of cycle position during power failureor accidental shutoff. The valve apparatus includes a generally flatvalve plate or disc 386 mounted for rotation with drive assembly 376within the top of pot housing 318. A mounting plate 388 supports thevalve plate to a flange 390 of quill shaft 374 by suitable means, suchas a plurality of mounting screws or the like. Valve disc 386 extendsoutwardly with a radius sufficient to cover a series of openingsprovided in the top of pot housing 318 and support plate 102. Asillustrated in FIGS. 10 and 18, these openings include a condenseroutlet opening 392 connected with condenser conduit 306, an air inlet394 connected with evacuation inlet conduit 310, and opening 104connected with throat section 98 of corn and salt hopper 58. An openingof disc hole 396 is formed in disc 386 uncovering openings 104, 392 and394 in accordance with the circuit program. A screen 393 covers opening392 and prevents corn from entering conduit 306.

Valve drive assembly 376 includes a gear 398 keyed to quill shaft 374,which in turn is journaled for rotation within an upstanding sleeve 400mounted above opening 402 provided in support plate 102. Gear 398 isdriven by suitable means such as an electric motor 404 mounted onbracket 380 and in driving connection with the gear through a suitablepinion gear 406, or the like, as illustrated in FIG. 9.

Different processes of the control circuit are triggered by a pluralityof switches actuated responsive to gear 398 rotation, and therefore inexact timed relationship with rotation of valve plate 386. Referring toFIG. 18, a start switch 408, a fill switch 410, a cook switch 412, andan evacuation switch 414 are mounted on a suitable bracket, not shown,around the periphery of gear 398. Start switch 408 is positioned on aradial line bisecting the angle between fill opening 104 and evacuationinlet 394. Fill switch 410 is positioned on line with fill opening 104.Cook switch 412 is positioned on line with condenser outlet opening 392.Evacuation switch 414 is positioned on line with evacuation inlet 394.These switches are actuated by suitable operating means on gear 398,shown as a switch operating roller or cam 416 attached to the gear andpositioned on a line centered on disc hole 396.

Referring to the schematic circuit diagram of FIG. 19, switches 408,410, 412 and 414 are illustrated connected in the control circuit foroperating the circuit relays, timers and indicator lights, as explainedin greater detail hereinafter.

Evacuation of Effluent and Popped Corn

The system for evacuating the popped corn from the pot is illustrated inFIGS. 6 and 10 and includes a blower fan 418, preferably of a typeincluding a non-clogging paddle impeller. The fan is driven by suitablemeans such as an electric motor 420 through a suitable belt and pulleydrive arrangement 422. The fan inlet opens above a cover plate 424mounted over opening 426 above cylindrical portion 332 enclosing popcorndischarge 334. The fan discharges at connection 428 into evacuationinlet conduit 310.

When valve disc opening 396 is in vertical registry or alignment withevacuation inlet opening 394, blower 418 is energized to draw intake airfrom cone 46 and direct it into the pot through conduit 310 and opening394. A deflector plate 430, preferably of a flat, circularconfiguration, is mounted within the pot by suitable means, such as abracket 432 secured to the outside of conduit 312 at a position spaceddirectly below inlet 394. Deflector plate 430 functions to direct theincoming air stream outwardly and downwardly around the inside peripheryof the pot in a sweeping motion. This enhances the efficiency of popcornevacuation so that the air stream sweeps the popcorn across the bottomof the hot-plate, upwardly into evacuation conduit 312, and downwardlythrough cone 46 into the display case. The stream of air issuing fromoutlet 334 in cone is recirculated and drawn upwardly through the blowerintake. During this evacuation cycle, valve plate 386 closes offcondenser outlet 392.

After a filling cycle with the corn and salt charged into the pot, motor404 indexes valve disc 386 until valve hole 396 opens communication withcondenser outlet 392, and at the same time cam roller 416 actuatesswitch 412 to initiate the cook cycle. The control circuit actuatessolenoid 284 of oil reservoir 166 for dumping the charge of seasoningoil through opening 288 into the pot. As the cooking cycle continues,the oil is heated by the hot plate while the agitator rotates. Steamdriven from the corn and waste oil evolved within the pot are removedthrough outlet 392 into condenser system 308. During the cook cycle,motor 404 stops the valve disc with its opening at the condenser outletposition until the corn is popped and the control circuit initiates theevacuation cycle.

Steam and Waste Oil Condensing System

Condensing system 308 is adapted to draw the steam and waste oileffluent from the pot by vacuum, and to condense the same byself-cleaning action without escaping into the surrounding room. Thecondenser system comprises an upstanding shell 434 mounted at the rearof frame 12. Effluent from the pot is directed through conduit 306 intoan upper inlet header 436 communicating with a plurality of downwardlyextending heat exchange tubes 438. The tubes 438 communicate at theirlower end with a chamber 440 for reverse flow upwardly along a pluralityof upwardly extending heat exchange tubes 442 discharging into outletheader 444 and outlet tube 446.

A partition 448 divides shell 434 into two air channels 450 and 452enclosing respective tubes 442 and 438. Cooling air from a condenserblower 454, as best seen in FIG. 4, is supplied from within lowersection 14 of the machine and directed into inlet opening 456 of shell434. The cooling air is forced upwardly for cooling and condensing thesteam and waste oil. Opening 458 in partition 448 combines the flow fromchannel 452 with that of channel 450 for delivery through a venturi ornarrowed throat section 460 adjacent the discharge end of tubes 442. Theincreased air flow and lowered static pressure at the venturi creates avacuum within tubes 442 acting to draw the steam and waste oil throughthe condenser tubes from the pot in the flow path illustrated in FIG. 5.

Condensed steam and oil droplets forming on the inside surface of thecondenser tubes drop downwardly by gravity to collect on the bottom ofchamber 440 where it drains through outlet 462 into a removablecondensate drain pan 464.

FIG. 20 illustrates a modified form embodying a steam condenser,illustrated generally at 466. Condenser 466 replaces outlet conduit 306between condenser outlet 392 and condenser header 436 in the preferredform of FIG. 6, and functions to immediately condense steam as it leavesthe pot. The water condensate is collected and drained away preventingits return to the pot. This results in a dryer popcorn having improvedflavor and tenderness.

Condenser 466 comprises an upwardly extending tube section 468 mountedover condenser outlet 392 on support plate 102. Conduit section 470encloses at one end upper lip 472 of the tube and extends downwardlytherefrom to an outlet 474 mounted to the inlet of condenser header 436by suitable fasteners provided on mounting flange 476. A dome or cap 478is mounted above an opening 480 provided in conduit 470 directly abovethe tube. Tube lip 472 is radially spaced inwardly from conduit endportion 482 to define a collecting gutter 484. A conical screen 486mounted above tube lip 472 prevents kernels of corn from entering thecondenser air stream. In operation, steam and waste oil particles drawnfrom the pot by the vacuum created in the condenser during a cookingcycle enters tube 468 and impinges on both screen 486 and the innersurface of cap 478. The lower temperatures of these elements functionsto condense the steam which collects and runs downwardly into gutter484, the lower surface of conduit 470, and through tubes 438 ofcondenser 308 for delivery into condenser outlet drain 462. After thecooking cycle, when the condenser outlet is closed by the valve plate,the elements of condenser 466 lose the heat received from the condensedsteam and cool down for the following cooking and condensing cycles.

Removal of "Old Maids"

In the form of the invention illustrated in FIGS. 1-4 the "old maids" orunpopped kernels are removed from pot 18 along with the popcorn and aredelivered into display case 16 where they fall onto screen 44. Thekernels either drop through the screen into fine collector tray 488unassisted, or else are scraped onto the screen by the operator. Fromtray 488 the kernels are directed through fine chute 490 downwardly intoremovable bin 492 provided at the bottom of the frame.

In the modified form illustrated in FIG. 21, an alternate "old maid"removal system is indicated generally at 494. This system comprises akernel trap device 496 including a lower tubular portion 498 extendingdownwardly through an opening in support plate 102 into the display caseand opening underneath at 499. An upper tube extension 500 projectsabove plate 102 into upper machine section 20. The trap may extendthrough an opening in top cover 502 with a transparent top cover or dome504 of a suitable material, such as Lucite plastic. This provides anattractive display of popcorn moving upwardly during an evacuationcycle. Popcorn issuing from the pot through evacuation conduit 312enters the trap through inlet connection 506 and is deflected upwardlyby means of partition 508. This partition comprises a vertical sectionof a cone removably attached within trap 496 and with its small endadjacent inlet 506 and its large end 510 opening upwardly within thetube. A lower section 512 of the partition is lockably hinged at 514 forcleaning purposes and extends downwardly in abutting relationship with atubular chute 516 extending downwardly from the trap to direct the "oldmaids" into bin 492 for subsequent removal.

In operation during an evacuation cycle, the popped corn and "old maids"are directed upwardly through conduit 312, then into opening 506 of thetrap. The popcorn is deflected upwardly by partition 508 and carried inthe channel between the tube and partition by the air stream until itcascades over upper end 510 and falls downwardly into the display case.The velocity of the air stream is high enough to blow the popcornupwardly but insufficient to lift the "old maids", which instead arecarried by gravity downwardly through opening 518 into chute 516. As aresult, the "old maids" are automatically removed from the popped corn.

Automatic Control Circuit

Referring to FIG. 19, a schematic diagram for automatic control circuit520 is illustrated. A suitable alternating current electric energysource 522 connected with main circuit breaker or switch 524 providesthe range of voltages required with the invention. For heating the hotplate heater 338, the circuit provides 240 VAC through the contacts ofstart switch or button 526 and temperature control switch 528 adapted toregulate plate temperature preferable at 410°F. Power at 120 VAC isprovided at 530 for operating various control elements includingagitator motor 378, valve disc motor 404, corn meter motor 80, seasoningpump motor 532 operating pump 178, motor 420 for powering emptying orevacuation blower 418, salt fill solenoid 150, and "total pop counter"536. The voltage from source 530 also operates power supply 538providing a suitable direct current control voltage, such as 26 VDC.This voltage powers the R.F generator 540 connected with both corn levelcapacitor plates 116, 118 and seasoning level plates 292, 294 and 296.This DC voltage further powers the "number of pops selector" control 542through relay 544 and provides an input 546 for start switch 408 andremaining elements of the circuit.

A corn level detector and switch 548 is provided for actuating switch550 and corn meter motor 80 responsive to a signal from capacitor plates116, 118 indicating that corn resupply in hopper 58 is required. If thecorn supply is adequate for one or more pops, a signal is directed intostart/complete "and" switch 522.

A seasoning level detector and switch 554 is provided to signalseasoning pump motor switch 556 and seasoning pump motor 532 to fill oilreservoir 166 responsive to a signal from seasoning level condenserplates 292, 294 and 296. Upon completion of the oil filling cycle, asignal is directed from switch 554 into "and" switch 552.

Salt level switch 146 provides a signal to "and" switch 552 forcontinued cycling only if sufficient salt is in bin 136 for thefollowing popping cycle. The "number of pops" selector 542 also providesa signal into switch 552 for recycling of the popping cycle only wherethe number of pops selected by the operator exceeds the total pop countreceived at input 557 following each energization of fill switch 410.The recycle signal from selector 542 also triggers operation of cornlevel detector 548.

The seasoning temperature is measured by low temperature limit 558 whichdirects a signal to both seasoning level detector/switch 544 and switch552 when the temperature of the oil is high enough for pumping andcirculation. Popper heater unit 560 provides a signal at 562 for both"and" switch 552 and seasoning level detector/switch 554 as a lowtemperature limit below which the cycle should not proceed. Popper unit560 provides a high temperature limit signal 564 into contactor controland interlink unit 566 above which temperature contactor solenoid 568 isdropped out to open switches 526 and discontinue heating current.

A popping rate or "pops per hour" selector 570 is provided toselectively vary the time delay between pops by controlling start timedelay switch 572. Switch 572 functions to close within a range of time,for example from 10 seconds to 8 minutes, after receiving a start signalfrom switch 552. This provides automatic popping rate control which canbe selectively changed at any time, depending upon popcorn consumption,without affecting the other settings.

Actuation of start or ready switch 408 to its normally closed position598 triggers agitator switch 572 for operating agitator motor 378, andconditions contactor control 566 for operation. Actuation of switch 408to the illustrated start or ready position by cam 416 triggers operationof corn level detector/switch 548 when relay 574 is closed by contactorsolenoid 568. The normally closed position of switch 408 operates as ahold circuit for contactor control 566 holding solenoid 567 energized toclose relays 526, 544 and 574.

Operation of fill switch 410 by cam 416 triggers both fill and countswitch 576 and directs a count signal 557 into pops selector 542. Switch576 in turn actuates salt fill solenoid 150 and total pop counter 536.

With cook or pop switch 412 in its normally closed position, and withstart switch 408 in its normally closed position, a circuit is completedfrom power input 546 through switches 408, 412 and 414 for actuatingvalve disc switch 590 and operating motor 404 to rotate the valve discpast the fill position until it reaches the cook position. When coolswitch 412 is actuated by cam 416, time delay 582 is triggered foroperating seasoning fill solenoid 284, which automatically turns offwithin 10 seconds. The circuit to switch 590 is opened for stopping thedisc at the cook position. Switch 412 further operates time delay 584which closes within 2-3 minutes to then actuate switch 590 and motor 404to rotate the disc to the evacuation position, where it stops duringpopcorn evacuation.

When the evacuation or empty switch 414 is operated by cam 416 to its"empty" position, a signal is directed to energize the empty start andrun switch 586 which energizes blower motor 420 for emptying popcornfrom the pot. A signal is also directed into normally open time delayswitch 588 which closes after a predetermined time delay of, forexample, 35 seconds. When switch 588 closes, switch 590 is closed tooperate motor 404 to rotate the valve disc back to the start position.

OPERATION

Assuming that the machine is initially cold and that the corn bin, oilbucket and salt hopper have been replenished, operation is initiated byclosing main switch 524. This directs power to start button 526, toseasoning heaters 196, 198, and to the lights and operating switches ofcontrol panel 48. Main switch 524 also turns on blower motors 62 and 454for continuous operation.

Pop selector control 542 is then adjusted to the desired number of pops.An indicator light, not shown, associated with this control indicateswhich pop in the cycle the machine is at, and the selector pointerindicates at which pop it will stop.

Pop rate selector 570 is adjusted to vary the popping rate by addingdifferent time delays between pops. For example, a 10-second delay wouldbe provided for a rate of 15 pops per hour, a 2-minute delay for a rateof 10 pops per hour, and an 8-minute delay for a rate of 5 pops perhour.

After a sufficient warm-up time on the order of 15 minutes, the contactsof start button or switch 526 are closed by the operator. This directspower through temperature control switch 528 to popper heater unit 560.Relays 544 and 574 are also closed by the start button. Where the totalnumber of pops in control 542 has been set at one or more, than arecycle signal 592 is directed into both switch 552 and contactorcontrol 566. The signal to control 566 operates as a hold circuitthrough contactor solenoid 568, holding switch 526 closed if the hightemperature limit signal 546 and agitator motor signal 594 indicateproper functioning of the heater and agitator.

Start switch 408 in the start or ready position of the valve disc isoperated by cam 416 to direct power through relay 574 ad into corn leveldetector/switch 548. With no corn in supply reservoir 82, capacitorplates 116, 118, signal switch 548 for closing switch 550 and operatingcorn meter motor 80 to inject a supply of corn into the air conveyoruntil the reservoir is filled to a position between the plates. Thisfill time takes approximately 21/2 minutes, after which time a cornsupplies indicator light, not shown, lights up.

Power is also directed through relay 574 into seasoning leveldetector/switch 554. During the warm-up period, the heaters surroundingpump unit 178 have melted a sufficient amount of oil at the pump intakeand within feed line 164. With no oil in reservoir 166, the seasoninglevel capacitor plates 292 and 294 signal switch 554 to energize switch556 and seasoning pump motor 532, provided that the low temperaturelimit signal 562 from the heater unit indicates proper heatertemperature and that the signal from seasoning low temperature limit 558indicates proper seasoning temperature. Seasoning pump 178 operates tofill reservoir 166 until the liquid level is between plates 296 and 294,at which time a signal is produced at 596 into switch 552 for initiatingthe popping cycle, provided the remaining inputs to switch 552 andpresent.

When all conditions for initiating popping are present including theheater signal 562, corn level switch 548 indicating resupply of the cornreservoir, seasoning level switch 554 indicating resupply of the oilreservoir, salt level switch 146 indicating sufficient salt supply, andthe number of pops is one or more, then a signal is directed to timedelay switch 572. Switch 572 closes after the preselected time delay todirect a signal to switch 590 for energizing disc motor 404. This motorturns valve disc 106 to the fill position where valve opening 396exposes fill opening 104. The corn in reservoir 82 drops by gravity andthe air current from air conveyor conduit 70 through throat section 98into the pot. The valve disc is driven past the opening 104 withoutstopping and cam 416 momentarily actuates fill switch 410 to triggerfill and count switch 576 for actuating salt fill solenoid 150 and totalpop counter 536. Solenoid 150 moves charging valve 134 to drop the saltin valve cavity 156 into the air stream which carried it into the pot.At the same time, switch 410 triggers a pop count signal 557 to reduceby one the number of pops set into selector control 542.

After the valve disc leaves its start position, cam 416 releases startswitch 408 to its normally closed position at 598, directing power intoagitator switch 572 for operation of the agitator motor, and intocircuit 600 as a hold circuit into contactor control 566 and solenoid568.

Operation of start switch 408 to the position at 598 also directs powerthrough circuit 602, through the normally closed switches 412 and 414,and through diode 604 into valve disc switch 590 for continued operationof disc motor 404 up to the cook position.

When the valve disc drives to the cook position the circuit to switch590 is opened by cam 416 stopping the disc with disc opening 396 openingcommunication with condenser outlet 392. Switch 412 then directs powerthrough circuit 606 for operating time delay switches 582 and 584.Switch 582 operates seasoning oil fill solenoid 284 to open dump valveassembly 272 and drain the charge of oil into the pot through oil inlet288. Time delay 582 opens the circuit to the solenoid after a timeperiod of 10 seconds, which is adequate for draining a maximum oilcharge of 10 ounces. Time delay switch 584 closes after a preselectedtime within the range of 2-3 minutes. This is the dwell time at whichthe disc is in the cook position, and this dwell time is selectivelyadjusted within the range and desired for varying cooking time. Switch584 closes after the preselected time and directs a signal at 608 intovalve disc switch 590 to start the disc towards the evaculationposition. As the disc moves, cam 416 permits cook switch 412 to returnto its normally closed position providing a hold circuit into switch 590for continued disc operation.

Throughout the cooking cycle the corn is popped in pot 18 and steam andoil effluent is automatically removed through opening 392 and conduit306 by the action of the vacuum created within condenser 308 by the airstream from continuously operating blower 454.

At the cook position of the disc, actuation of switch 412 also directs asignal through circuit 606 into branch circuit 610 to signal corn leveldetector and switch 548. Switch 548 has received a signal from plates116, 118 indicating that resupply of corn reservoir 82 is required forthe next cycle, and has also received a signal at 612 from pop selector542 indicating that an additional pop is required. When these signalsare received, switch 548 triggers switch 550 for operation of corn metermotor 80 to recharge the corn reservoir.

After the cooking cycle, the valve disc is rotated to the evacuationposition, exposing evacuation inlet 394. When cam 416 reaches theevacuation position, switch 414 is actuated to trigger both empty switch586 and time delay switch 588. Switch 586 operates empty blower motor520 which directs an air stream into opening 394 sweeping the corn intoevacuation conduit 312 for delivery to the display case. Movement ofswitch 414 from the normally closed position opens the circuit to valvedisc switch 590 for stopping the disc at the evacuation position. Afterthe predetermined time delay of 35 seconds switch 588 closes to direct asignal to switch 590 and start the valve disc moving to the startposition. After cam 416 passes the evacuation position, switch 414returns to its normally closed position, providing a holding circuitinto switch 590 for continued operation of the disc.

When the disc reaches the start position, cam 416 actuates switch 408 toits open position, terminating power to the hold circuit for stoppingthe disc motor. At the same time, a signal is directed through switch408 into relay 574 and seasoning level detector and switch 554. Anabsence of oil in reservoir 166 signals detector switch 554, whichtogether with the signals from low temperature limit switch 558 andpopper low temperature limit 562, trigger seasoning pump switch 556 fora repeat of the oil reservoir refill for a subsequent cycle.

The machine is stopped by turning pops selector 542 to the stop positionfor terminating signal 592. If stopped before the cook cycle hasstarted, the control circuit will continue cycling and stop after theempty or evacuation cycle to insure that the effluent and popped cornhas been completely removed from the pot. If the pop selector is turnedto stop after the cook cycle has started, it will finish popping andthen make one more popping cycle before a final stop. This leaves themachine in shut-down condition with no corn in upper hopper 58, and nooil in reservoir 166.

The following is a preferred timing chart indicating cycling timesthroughout one complete popping operation. It is understood that thecycle times are illustrative only and may be varied according tooperating conditions and results desired. In this particular example,selector control 542 is set for two or more pops and rate selector 570is set at 15 pops per hour.

    ______________________________________                                        Time/Seconds                                                                            Condition or Operation                                                                              Program                                       ______________________________________                                        0         Main switch on, start button                                                                        Start                                                   pressed, all indicator lights on.                                   10        Corn reset, seasoning reset, and                                                                    Start                                                   start lights go out, indicating                                               corn and seasoning charges ready.                                   12        Disc motor drives past fill                                                                         Fill                                                    position, dumping corn as it                                                  passes. Salt solenoid fires                                                   when disc hole directly under                                                 hopper opening.                                                     14-16     Disc motor turns to con-                                                                            Fill                                                    denser outlet for cook cycle.                                                 On reaching cook position,                                                    dump valve for seasoning opens.                                     16        Corn metering motor starts. Con-                                                                    Cook                                                    densing of steam and waste season-                                            ing starts.                                                         26        Seasoning dump valve closes.                                                                        Cook                                          190       Corn metering motor stops.                                                                          Cook                                          200       Disc motor turns disc to empty                                                                      Cook                                          204       Evacuation motor starts.                                                                            Empty                                         236       Evacuation motor stops. Disc                                                                        Empty                                                   motor turns disc to start posi-                                               tion.                                                               240/0     Corn, salt, and start lights go                                                                     Start                                                   on and seasoning pump starts,                                                 with seasoning light on if cycle                                              is to be repeated.                                                  ______________________________________                                    

From the foregoing it is apparent that applicant has provided animproved popcorn popping method fully automatic in operation, and whichprovides a popped corn product of improved flavor, tenderness andappearance. While the embodiments herein are considered to be preferred,it is understood that numerous variations and modifications in thesteps, arrangement of parts, and materials may be made by those skilledin the art within the spirit and scope of the invention.

We claim:
 1. The method of removing popped corn from the closed pot of apopcorn popping machine in which popcorn has been cooked in heatedseasoning oil, including the steps of: maintaining the pot closed exceptfor an air inlet opening and an evacuation outlet: directing an aircurrent through the air inlet opening into the pot; carrying the poppedcorn and unpopped kernels out of the pot with said air current throughthe evacuation outlet; directing the air current with the evacuatedpopped corn and kernels along a path whereby the kernels drop downwardlyby gravity and the popped corn is directed along a path separated fromthe kernals; and collecting the kernels for removal from the machine. 2.The method of claim 1 in which the air current after being directedthrough the inlet opening is dflected outwardly and downwardly along theinside periphery of the pot, thereafter directing the air current acrossthe bottom of the pot to sweep the popped corn and unpopped kernelstoward the center of the pot, and thereafter directing the air currentupwardly through said evacuation outlet.
 3. The method of claim 2 inwhich the popped corn is separated from the air current and the aircurrent is recirculated in a path back into said air inlet.
 4. A methodof removing popped corn from the closed pot of a popping machine inwhich popcorn has been cooked in heated seasoning oil, including thesteps of: directing an air current downwardly through an upper inletopening of the pot, directing the air current along the bottom of thepot and toward the center thereof to entrain along popped corn andunpopped kernels, discharging the air current and entrained corn andkernels from the pot through an evacuation conduit, directing thedischarged air current in a path which curves downwardly and thenupwardly whereby the corn and kernels are separated from the air currentand directed downwardly therefrom, and thereafter recirculating the aircurrent into the pot through said inlet opening.